• 제목/요약/키워드: tardiness

검색결과 144건 처리시간 0.024초

다기능 레이더의 임무 스케줄링 및 복수 운용 개념 분석 (Task Scheduling and Multiple Operation Analysis of Multi-Function Radars)

  • 정순조;장대성;최한림;양재훈
    • 한국항공우주학회지
    • /
    • 제42권3호
    • /
    • pp.254-262
    • /
    • 2014
  • 레이더 임무 스케줄링은 제한된 자원 환경에서 레이더의 성능을 향상시키기 위해 효과적으로 임무 배치를 하는 것이다. 본 논문에서는 다기능 레이더의 복수 운용 시의 스케줄링 성능 평가를 위해 총 지연 시간의 합을 목적함수로 정의하고, 실시간성을 고려한 휴리스틱 접근법을 제시한다. 제안된 스케줄링 기법들을 일반적인 임무 시뮬레이션 환경에서 비교 분석하였으며, 특히, 다기능 레이더의 복수 운용에서의 스케줄링 성능을 분석한다.

재작업이 존재하는 이종병렬기계에서 생산효율을 위해 공정소요시간 단축을 목적으로 하는 작업할당 (Dispatching to Minimize Flow Time for Production Efficiency in Non-Identical Parallel Machines Environment with Rework)

  • 서정하;고효헌;김성식;백준걸
    • 대한산업공학회지
    • /
    • 제37권4호
    • /
    • pp.367-381
    • /
    • 2011
  • Reducing waste for the efficiency of production is becoming more important because of the rapidly changing market circumstances and the rising material and oil prices. The dispatching also has to consider the characteristic of production circumstance for the efficiency. The production circumstance has the non-identical parallel machines with rework rate since machines have different capabilities and deterioration levels in the real manufacturing field. This paper proposes a dispatching method, FTLR (Flow Time Loss Index with Rework Rate) for production efficiency. The goal of FTLR is to minimize flow time based on such production environments. FTLR predicts the flow time with rework rate. After assessing dominant position of expected flow time per each machine, FTLR performs dispatching to minimize flow time. Experiments compare various dispatch methods for evaluating FTLR with mean flow time, mean tardiness and max tardiness in queue.

Common Due-Date Assignment and Scheduling with Sequence-Dependent Setup Times: a Case Study on a Paper Remanufacturing System

  • Kim, Jun-Gyu;Kim, Ji-Su;Lee, Dong-Ho
    • Management Science and Financial Engineering
    • /
    • 제18권1호
    • /
    • pp.1-12
    • /
    • 2012
  • In this paper, we report a case study on the common due-date assignment and scheduling problem in a paper remanufacturing system that produces corrugated cardboards using collected waste papers for a given set of orders under the make-to-order (MTO) environment. Since the system produces corrugated cardboards in an integrated process and has sequence-dependent setups, the problem considered here can be regarded as common due-date assignment and sequencing on a single machine with sequence-dependent setup times. The objective is to minimize the sum of the penalties associated with due-date assignment, earliness, and tardiness. In the study, the earliness and tardiness penalties were obtained from inventory holding and backorder costs, respectively. To solve the problem, we adopted two types of algorithms: (a) branch and bound algorithm that gives the optimal solutions; and (b) heuristic algorithms. Computational experiments were done on the data generated from the case and the results show that both types of algorithms work well for the case data. In particular, the branch and bound algorithm gave the optimal solutions quickly. However, it is recommended to use the heuristic algorithms for large-sized instances, especially when the solution time is very critical.

품질과 납기를 동시에 만족하는 작업투입 개선에 관한 연구 (Improved Dispatching Algorithm for Satisfying both Quality and Due Date)

  • 윤지명;고효헌;백종관;김성식
    • 한국산학기술학회논문지
    • /
    • 제9권6호
    • /
    • pp.1838-1855
    • /
    • 2008
  • 생산 공정의 효율화는 모든 제조 산업이 추구하고 있는 목표이다. 본 논문에서는 다양한 타입의 제품을 병렬기계에 투입 할 때 목표한 품질을 만족시키고 동시에 평균 납기지연 시간을 최소화 하는 효율적인 작업투입방법에 대하여 기술하였다. 본 연구에서는 품질을 고려하고 실시간으로 작업을 투입해야 하는 공정에서 Rolling Horizon 타부탐색(Tabu search)방법을 이용하여 평균 납기 지연시간을 최소화 하는 방안을 개발하였다. 시뮬레이션을 통해 제안하는 방법의 효율성을 비교대안과 비교하였다. 본 방법은 실제 생산 공정에서 품질과 납기를 동시에 만족 시킬 수있는 효율적인 작업투입 방법으로 사용되어 기업의 수익향상과 신뢰성 확보를 이룰 수 있다.

An Efficient PSO Algorithm for Finding Pareto-Frontier in Multi-Objective Job Shop Scheduling Problems

  • Wisittipanich, Warisa;Kachitvichyanukul, Voratas
    • Industrial Engineering and Management Systems
    • /
    • 제12권2호
    • /
    • pp.151-160
    • /
    • 2013
  • In the past decades, several algorithms based on evolutionary approaches have been proposed for solving job shop scheduling problems (JSP), which is well-known as one of the most difficult combinatorial optimization problems. Most of them have concentrated on finding optimal solutions of a single objective, i.e., makespan, or total weighted tardiness. However, real-world scheduling problems generally involve multiple objectives which must be considered simultaneously. This paper proposes an efficient particle swarm optimization based approach to find a Pareto front for multi-objective JSP. The objective is to simultaneously minimize makespan and total tardiness of jobs. The proposed algorithm employs an Elite group to store the updated non-dominated solutions found by the whole swarm and utilizes those solutions as the guidance for particle movement. A single swarm with a mixture of four groups of particles with different movement strategies is adopted to search for Pareto solutions. The performance of the proposed method is evaluated on a set of benchmark problems and compared with the results from the existing algorithms. The experimental results demonstrate that the proposed algorithm is capable of providing a set of diverse and high-quality non-dominated solutions.

Effective simulation-based optimization algorithm for the aircraft runway scheduling problem

  • Wided, Ali;Fatima, Bouakkaz
    • Advances in aircraft and spacecraft science
    • /
    • 제9권4호
    • /
    • pp.335-347
    • /
    • 2022
  • Airport operations are well-known as a bottleneck in the air traffic system, putting growing pressure on the world's busiest airports to schedule arrivals and departures as efficiently as possible. Effective planning and control are essential for increasing airport efficiency and reducing aircraft delays. Many algorithms for controlling the arrival/departure queuing area are handled, considering it as first in first out queues, where any available aircraft can take off regardless of its relative sequence with other aircraft. In the suggested system, this problem was compared to the problem of scheduling n tasks (plane takeoffs and landings) on a multiple machine (runways). The proposed technique decreases delays (via efficient runway allocation or allowing aircraft to be expedited to reach a scheduled time) to enhance runway capacity and decrease delays. The aircraft scheduling problem entails arranging aircraft on available runways and scheduling their landings and departures while considering any operational constraints. The topic of this work is the scheduling of aircraft landings and takeoffs on multiple runways. Each aircraft's takeoff and landing schedules have time windows, as well as minimum separation intervals between landings and takeoffs. We present and evaluate a variety of comprehensive concepts and solutions for scheduling aircraft arrival and departure times, intending to reduce delays relative to scheduled times. When compared to First Come First Serve scheduling algorithm, the suggested strategy is usually successful in reducing the average waiting time and average tardiness while optimizing runway use.

다목적 유전 알고리즘을 이용한 실시간 태스크의 정적 스케줄링 기법 (A Multiobjective Genetic Algorithm for Static Scheduling of Real-time Tasks)

  • 오재원;김희천;우치수
    • 한국정보과학회논문지:소프트웨어및응용
    • /
    • 제31권3호
    • /
    • pp.293-307
    • /
    • 2004
  • 본 본문에서는 다중 처리기 시스템에서 실시간 태스크를 정적으로 스케줄링하기 위한 새로운 기법을 제안한다. 태스크는 실행 시간과 마감시간을 지니고, 태스크 사이에는 선행 관계가 존재하며 이러한 사항을 태스크 그래프로 표현한다. 본 논문에서는 스케줄링을 위해 사용하는 처리기의 개수를 줄이면서 태스크들의 마감시간 지연의 총합을 최소화하는 스케줄을 생성하는 것에 목적을 둔다. 이 문제는 같은 단위로 측정할 수 없고 또한 서로 상충하는 두 가지 목적을 지닌 것이다. 그렇지만 기존 방법들은 마감시간 지연의 총합만을 최소화하려하거나 두 가지 목적을 하나의 기준으로 결합시킨 후 최적화하고자 한다. 본 논문에서는 두 개의 목적을 독립적으로 고려하며 최적화를 위하여 다목적 유전 알고리즘을 사용한다 태스크 스케줄링 문제에 적합한 문제 표현 전략, 우세 개념에 기초한 선택 연산, 그리고 교차 연산을 제시한다. 그리고 지역 개선 작업을 위해 세 개의 휴리스틱을 제안하였으며 이 것을 통해 유전 알고리즘의 수렴성을 높이고자 하였다. 성능 평가를 위해 기존에 알려진 유전 알고리즘과 4 개의 리스트 스케줄링 알고리즘과 비교한다. 평가 결과를 보면 제안한 기법이 180 개의 임의로 생성한 태스크 그래프 중에서 178 개에 대해 기존 5 개의 알고리즘과 유사하거나 더 나은 스케줄을 생성하였다.

NO-WAIT OR NO-IDLE PERMUTATION FLOWSHOP SCHEDULING WITH DOMINATING MACHINES

  • WANG JI BO;XIA ZUN QUAN
    • Journal of applied mathematics & informatics
    • /
    • 제17권1_2_3호
    • /
    • pp.419-432
    • /
    • 2005
  • In this paper we study the no-wait or no-idle permutation flowshop scheduling problem with an increasing and decreasing series of dominating machines. The objective is to minimize one of the five regular performance criteria, namely, total weighted completion time, maximum lateness, maximum tardiness, number of tardy jobs and makespan. We establish that these five cases are solvable by presenting a polynomial-time solution algorithm for each case.

다중플랜트 네트워크에서의 공급사슬계획 (Supply Chain Planning in Multiplant Network)

  • 정재혁;문치웅;김종수
    • 한국산업경영시스템학회:학술대회논문집
    • /
    • 한국산업경영시스템학회 2002년도 춘계학술대회
    • /
    • pp.203-208
    • /
    • 2002
  • In case of the problems with multiple plants, alternative operation sequence, alternative machine, setup time, and transportation time between plants, we need a robust methodology for the integration of process planning and scheduling in supply chain. The objective of this model is to minimize the tardiness and to maximize the resource utilization. So, we propose a multi-objective model with limited-capacity constraint. To solve this model, we develope an efficient and flexible model using adaptive genetic algorithm(AGA), compared to traditional genetic algorithm(TGA)

  • PDF

단일 기계의 일정계획 문제에 대한 지식 베이스 빔 탐색 기법 (A Knowledge-based Beam Search Method for a Single Machine Scheduling)

  • 김성인;김선욱;양허용;김승권
    • 대한산업공학회지
    • /
    • 제19권3호
    • /
    • pp.11-23
    • /
    • 1993
  • A basic problem of sequencing a set of independent tasks at a single facility with the objective of minimizing total tardiness is considered. A variation of beam search, called knowledge-based beam search, has been studied which uses domain knowledge to reduce the problem size with an evaluation function to generate nodes probable to include the optimal solution. Its performance behavior is compared with some existing algorithms.

  • PDF